Arterial compliance variation throughout the cardiac cycle

Arterial compliance is known to be pressure-dependent, but its variation within any given cardiac cycle has not been clearly illustrated. We reported first such evaluation by incorporating a nonlinear compliance in the form of C(P) = a exp(bP) substituting for the linear compliance in a three element modified windkessel model of the systemic arterial system. Results show that C(P) varies continuously with time throughout the cardiac cycle, reaching a minimum at end-systole. C(P) altered significantly with increasing or decreasing blood pressure.